Vacuuming the Reef

Super Sucker and his sidekick, Jr., to the rescue.

The phrase “Super Sucker” may provoke an immature chuckle. Yet it makes a perfect name for the underwater vacuum used to remove the alien algae smothering O‘ahu’s reefs.

Alien algae can be found on almost every island, and poses a serious threat to Hawai‘i’s reefs. On O‘ahu, the algae dominates large portions of Kane‘ohe Bay and the south shore, from west of Pearl Harbor to Maunalua Bay.

About four years ago, community volunteers started to remove the alien algae by hand, but it wasn’t tackling the problem on a large enough scale, or controlling the algae’s spread. The idea for the Super Sucker came from a planning meeting with the Division of Aquatic Resources, the University of Hawai‘i and the Nature Conservancy. Eric Co, the marine coordinator for the Nature Conservancy, was responsible for designing the vacuum. “Basically what you have is a means to remove alien algae in a very focused, controlled way,” says Co. With the Super Sucker, just five or six people can remove 800 pounds of algae in an hour.

The Super Sucker is equipped with a 40-horsepower engine—running on bio-diesel—and sits atop a 13-by-25-foot barge. Two divers carry a 4-inch hose to suck up the invasive algae, while the contents and 200 to 300 gallons of water per minute are deposited onto a screen table.

The device doesn’t use blades or fans; three sorters sift through the materials to check for inadvertently collected marine animals such as sea cucumbers, small crabs and the occasional fish, which are returned safely to the ocean.

The Super Sucker was tested in the southern portion of Kane‘ohe Bay, on a particularly destructive algae species called Gracilaria salicornia, which forms thick mats that kill coral and clog reef habitats used by fish. The area has now been clear for nearly one year, since the pilot program first started.

With the test a success, the real work could begin. “We’re now up in the northern portion of Kane‘ohe Bay, called Reef 44, so we’re using the Super Sucker in the outer reaches of the algae’s distribution area where we can help control the spread of it,” says Co.

In 2007, the Super Sucker Jr., will make its debut as a smaller, more easily transportable machine that will likely be used on the south shore of O‘ahu and in more remote locations.

The larger strategy includes replanting the reefs with native algae species, and introducing native algae-eating sea urchins—which prefer to munch on the invasive species.

So where does all the collected alien algae go? Local farmers are using it as a fertilizer to grow taro, while other people request it for everything from research to making poke.